Cross-linked chitosan-coated liposomes for encapsulation of fish-derived peptide

The aim of this work was to develop novel hybrid nanocarriers made of liposomes coated with chitosan (CS) cross-linked with sodium tripolyphosphate (TPP), named CS-TPP/liposomes, for fish-purified antioxidant peptide fractionated by RP-HPLC (F5). The produced nanodispersion (peptide-loaded CS-TPP/liposomes) was characterized by dynamic light scattering (DLS), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, and differential scanning calorimetry (DSC). The mean nanoparticle sizes of these uncoated and CS-TPP coated liposomes were found to be 409.2 and 687.4 nm, respectively, and the obtained polydispersity index (PDI) was ≤0.2. HRTEM revealed the spherical shape and smooth surface of the produced peptide-loaded nanovesicles. FT-IR spectroscopy revealed that the liposomes have been successfully coated by CS-TPP. In addition, DSC findings indicated enhanced electrostatic interactions among CS and lecithin molecules, leading to an increase in the melting (Tm) and decomposition temperature (Td) in peptide-loaded CS-TPP/liposomes hybrid system. Furthermore, the antioxidant activity of the loaded fish-purified antioxidant peptide to CS-TPP/liposomes was retained as confirmed by the employed free radical scavenging assay. The proposed hybrid system represents a promising idea for the delivery of protein hydrolysate and peptide fractions thereof in nutraceutical and functional foods applications.